1. Field of the Invention
The present invention relates to a small vessel propulsion system preferably for use in a small vessel, such as a jet propelled watercraft, an outboard motor craft, etc. A small vessel refers to a vessel with a gross tonnage of less than 20 tons. However, a vessel with a gross tonnage of not less than 20 tons is included in small vessels if its length is less than 20 meters.
2. Description of the Related Art
A jet propelled watercraft includes a jet pump that jets water rearward from a jet port and a reverse gate that changes a direction of the jet flow jetted from the jet pump. The reverse gate is movable, for example, among a forward drive position, a reverse drive position, and a neutral position in between. The forward drive position is a position at which no portion of the jet port is covered by the reverse gate in a rear view viewed along a jetting direction of the water jetted from the jet port. The reverse drive position is a position at which an entirety of the jet port is covered by the reverse gate in the rear view. The neutral position is a predetermined position between the forward drive position and the reverse drive position.
With a jet propelled watercraft or other small vessel, travel within a slow-speed zone in which travel speed is limited or travel in shallow waters may be performed over a long period of time. However, a vessel operator tends to become tired when travel while maintaining a low speed state is performed over a long period of time because accelerator operation is monotonous. Japanese Patent Application Publication No. 2006-200442 thus disclosed a jet propelled watercraft having, as a travel mode, a low-speed travel mode (low-speed setting mode) of traveling at a predetermined low speed set in advance. This jet propelled watercraft includes a low-speed travel mode switch (low-speed setting switching) arranged to switch the travel mode to the low-speed travel mode.